This is why Lucy has been the face of human evolution for the last 50 years (2024)

The first clue that the fossilized human ancestor known as Lucy would be a global phenomenon came at a Paris airport in December 1974. While passing through customs, paleoanthropologist Donald Johanson introduced the wrapped parcels in his bag as fossils from Ethiopia, and a customs official replied, “You mean Lucy?”

Just a few weeks earlier, Johanson and his team had discovered the bones of a small adult female, who appeared to be a long-lost member of our family tree. The ancient skeleton had yet to be examined and analyzed by researchers, but a press release had been enough to catapult her toward becoming arguably the most well-known fossil in history.

At the time, there was “significant broad interest in human origins,” Johanson says. Finds by the Leakey family and other scientists in South Africa had begun filling in the human story, suggesting that early ancestors evolved upright posture millions of years ago in Africa, followed later by large brains and the ability to use tools.

Yet the fossils unearthed so far were fragmentary—a skull here, a partial foot there. And they dated to no more than 1.75 million years old, significantly younger than humans’ most distant ancestors were suspected to be.

Lucy would go on to set records in age and completeness, while confirming ideas about humans’ evolutionary transition to upright walking. Other fossils have since surpassed her in achievements, but Lucy remains a household name 50 years later. The fossil’s scientific story has been entwined with a cultural one from the very beginning.

The lore of Lucy’s discovery

On November 24, 1974, Johanson was searching for fossils of ancient human relatives or hominins in an area called Hadar in the Afar region of Ethiopia, when he noticed a forearm bone eroding out of a hillside. Collecting the bone and returning to camp, Johanson and the field team celebrated that evening, singing along to the popular Beatles song, “Lucy in the Sky With Diamonds” (or so the story goes). The next day, they excavated the rest of the hominin remains in 110-degree heat and started calling the skeleton Lucy. In scientific circles, she’s would later be known as AL 288-1, and in Ethiopia, as Dinkinesh, which mean “you are marvelous” in Amharic.

Piecing together her lower jaw, skull fragments, vertebrae, ribs, arms, a pelvis, and legs, the team collected approximately 40 percent of Lucy’s skeleton. She appeared to be a fully grown adult, yet stood just over a meter tall.

(Here’s one theory on how Lucy died.)

The volcanic rock layers sandwiching the fossils dated her to 3.2 million years old—almost doubling the age of what was then the oldest known human ancestor. Beyond that, the next oldest skeleton at the time dated to only 100,000 years old. Such an ancient, complete specimen was remarkable. Lucy hit all the superlatives, science writer for the New York Times Boyce Rensberger remembers, “the oldest and most complete.”

Based on the fragmented remains of her skull and other finds at Hadar, Lucy seemed to have a small, chimpanzee-sized brain and projecting face, but the rest of her skeleton indicated a fully erect, human-like posture. In 1978, Johanson and colleagues officially assigned her to a new species, Australopithecus afarensis (the southern ape from the Afar in Latin), and declared she was proof our ancestors walked on two legs before evolving large brains.

Yet even at the time, Lucy wasn’t the most controversial or earthshattering discovery in the history of human origins science. While she demonstrated that upright walking was an early hallmark of an African lineage, Africa had already been recognized as humanity’s birthplace for decades, as had the idea that upright posture preceded big brains.

Lucy’s cultural significance quickly expanded even beyond her scientific status. From the start, she had all the makings of an icon—her catchy nickname, her dramatic discovery. But perhaps most importantly, she had an enthusiastic narrator in Johanson. It proved to be a winning combination.

What propelled Lucy to stardom?

By 1974, the Leakey family—Mary, Louis, and their son Richard—had been unearthing ancestors for over a decade. Their discoveries of several skulls, stone tools, and other fossils from Olduvai Gorge in Tanzania and the shores of Lake Turkana, Kenya, had appeared in National Geographic and other magazines.

Despite frequently appearing in the news, ancestors found by the Leakeys with nicknames like Dear Boy and Nutcracker Man had never achieved such star power. “There just weren't any fossils that people in the United States or Europe were connecting to,” says Kaye Reed, a paleoanthropologist at Arizona State University.

(How did scientists almost miss the ‘missing link’ fossil?)

Lucy’s journey from an unknown in Ethiopia’s highlands to the kind of celebrity that gets recognized in an airport puzzles even Johanson. “I've been turning it over in my mind,” he admits, “trying to figure out what it was that attracted such an enormous amount of attention.”

Perhaps one facet is her exceptionally human nickname, which Johanson calls “affectionate and easy to remember.” Or maybe it has to do with the fact that the discovery “is a partial skeleton,” he muses, “and it can therefore be recognized as an individual.”

Others credit Johanson himself for “tirelessly” engaging in public communication of science. Indeed, Johanson’s book, Lucy: The Beginnings of Humankind published in 1981, catapulted up the bestseller list. The book led to appearances on programs like Good Morning America and a NOVA series “In Search of Human Origins,” filmed in Ethiopia. “Largely, we owe it to Johanson’s writings, interviews, and lectures,” says Zeray Alemseged, a paleoanthropologist at the University of Chicago.

At just 31 years old when he found Lucy, the young Johanson appeared equally at ease in front of a camera wandering the high desert as he did seated beside Walter Cronkite on primetime. Later media accounts described Johanson as “a man of great natural grace” and “Indiana Jones in Armani.” However, he recalls that he “was very awkward and much too technical” at first, before receiving guidance from science communicator Carl Sagan.

The combined factors of the nickname, completeness, and Johanson’s approach came together to paint Lucy as relatable. Far from treating her as a pile of dusty old bones, Johanson personalized her. In documentaries, for example, he often subtly reminds the viewer that she was once a living, breathing individual, referring to her discovery site not as merely the place where he came across her fossils, but also as “the very spot where she died all those years ago” in the NOVA series.

Human origins in the spotlight

Having such a personable ancestor helped thrust the science of human origins further into the spotlight than ever before. Harnessing the momentum, Johanson set up a non-profit institute called the Institute of Human Origins in Berkeley, California, in 1981. In addition to research and fieldwork, he decided that public outreach should be a pillar of the organization from the start.

Lucy provided a window through which to educate people, a way to reach out to both children and adults “and just say, this is what we do,” one of the Institute’s first faculty members, Reed, recalls.

Not everyone valued Johanson’s public-facing persona, however, causing a rift within the institute, as some researchers accused him of prioritizing public relations above science. The dispute ended with the departure of several geologists and a relocation to Arizona State University in 1997. That year, Johanson’s colleague William Kimbel argued in the Phoenix New Times that if scientists doing the work “are not in the position to communicate the results to the public, something is wrong.” So outreach, fundraising, and research continued progressing in tandem.

These efforts channeled funding toward fieldwork that helped A. afarensis become one of the best-represented species of human relative in the world. With over 400 specimens recognized across half a dozen sites in Ethiopia and Kenya, the majority of A. afarensis fossils come from Hadar, and researchers continue searching. Newer discoveries, including several mostly-complete skulls, have shown that the species lasted from 3.9 to 3 million years ago and ate a generalized diet, making them more flexible than previous hominins.

(What killed the hominins of AL 333?)

What is Lucy’s legacy?

Today’s human evolution researchers are the generation raised by Lucy. Chris Campisano, a paleoanthropologist at Arizona State University, remembers reading Johanson’s book in high school for a summer project, sparking his interest in searching for hominin fossils in Africa. Now, he leads the research at Hadar. Reflecting on the trajectory, Campisano remarks, “I never would have guessed that on the 50th anniversary of Lucy’s discovery, I’d be leading the project.”

Today, the institute that Lucy built still leads paleoanthropological research around the world. Combining education with fundraising to support research, the impact has proliferated far beyond Hadar.

The fossil’s stardom has had a “domino effect,” says Alemseged, who is Ethiopian and first met Lucy while working at the National Museum of Ethiopia in Addis Ababa, where she is currently stored in a specially constructed safe.

Alemseged was a postdoc at the Institute when he guided the first-ever Ethiopian-led team to the site of Dikika, just across the Awash River from Hadar. There, he found a remarkably complete child of Lucy’s species, A. afarensis he named Selam, meaning “peace” in Amharic. Only about 2.4 years old when it died, the child was quickly dubbed “Lucy’s Baby”—despite having lived 200,000 years before Lucy.

(Who were Lucy’s neighbors?)

Amid the ever-growing collection of A. afarensis fossils, Lucy remains at the center. “It's very difficult to not make reference to Lucy when you talk of new discoveries,” Alemseged says, adding that she has become the “benchmark” against which all other fossils are compared. “You find something and people ask, is it older or younger than Lucy? Taller or shorter than Lucy?”

Lucy is no longer the oldest or the most complete human ancestor. The 7-million-year-old Sahelanthropus tchadensis and the 6-million-year-old Orrorin tugenensis vie for the oldest title, while the skeleton of “Little Foot”, an Australopithecus from South Africa, is over 90 percent complete.

Yet Lucy’s icon status has yet to be repeated. As “Little Foot” suggests, scientists have tried nicknaming their finds, from “Ardi” short for Ardipithecus to “Neo” and “Child of Darkness” for various specimens of South Africa’s Homo naledi. These monikers haven’t caught on widely, however, and in the sky with diamonds, Lucy remains.